U.S. Pat. No. 8,096,655 to Daphna describes a hyper-osmotic contact lens designed to treat corneal edema. The hyper-osmotic contact lens absorbs fluid from an edematous cornea by the force of an osmotic gradient. The hyper-osmotic contact lens is designed as a microcontainer with walls that are thin relative to its general dimensions, and is shaped as a lens with anterior and posterior walls, which define and bound a hyper-osmotic chamber. The posterior wall, which is the area in which the cornea and the contact lens overlap, is made of a selective water permeable membrane. In this area, water from the edematous cornea can flow out of the cornea into the hyper-osmotic chamber by the force of osmosis, thus dehydrating the cornea itself. The hyper-osmotic chamber may contain a hyper-osmotic transparent medium such as dry hydrogel or solution such as glycerol, salts, etc.